Man… I’m soooo unsure about the size too...
I ride a Merida Scultura in size M, an ICAN A40 (Cinelli Pressure 1st gen) in size L, and both have almost the same reach…
But I have to push the saddle all the way forward on both of them to get the perfect pedal stroke...
Based on ChatGPT and my own calculations and comparisons on
https://geometrygeeks.bike/, the FM313 model would suit me best... and that’s in size S… but that just feels wrong somehow?!?!?!
It looks so small, too...

The 75° seat angle theoretically lets me sit better over the bottom bracket so I don’t have to sit all the way forward.
With size M, the reach would be huuuuge….
I’m 1.83 m tall with an 86 cm inseam...
I always ride aggressively when I’m out on this bike... meaning road bike on fast gravel, dirt roads, or forest roads... not so much for bikepacking, trails or leisurely rides... I’m usually riding with a certain amount of intensity
Can anyone offer some expert advice?